The present invention is concerned with a new method and apparatus for automatically applying reinforcing tabs to sheets held in loose-leaf binders to reinforce the holes in the sheets through which the rings of the binder pass.
A common problem encountered in using loose-leaf binders to hold sheets of paper and the like is the tendency of the sheets to rip or tear in the margin area of the sheet, between its edge and the hole in the sheet for the binder ring. The tendency of sheets to tear becomes more pronounced with use or when the binder is nearly full. To repair torn sheets or to prevent sheets from being torn, it is well known to reinforce the holes in the sheets with reinforcing tabs, such as annular rings of cloth, etc., which have a water-activated glue backing. One of the difficulties in using such reinforcing tabs is that the tabs cannot be conveniently applied to the loose-leaf sheets unless the sheets are removed from the binder. This is burdensome and time-consuming, particularly when repairing a large number of sheets.
To overcome this difficulty, reinforcing tabs capable of being applied without removing the sheets have previously been proposed. For example, U.S. Pat. No. 2,437,640 to Hendrick, issued Mar. 9, 1948, discloses C-shaped reinforcing tabs which can be placed around the rings and can be attached to the sheets in the binder. Double U-shaped tabs designed to fit around the edge of a sheet and attached to both sides thereof are disclosed in U.S. Pat. No. 2,589,168 to Vassar, issued Mar. 11, 1952. Split-rim reinforcing tabs comprising an aperture communicating with the periphery of the tab by a slot are disclosed in U.S. Pat. No. 3,315,683 to Rodriquez et al, issued Apr. 25, 1967. Although such tabs may be applied to loose-leaf sheets without removal of the sheets from the loose-leaf binder, all have the disadvantage of requiring manipulation by hand within the confined spaces of the rings of the binder. Furthermore, such tabs are still time-consuming to apply.
While the problems encountered in reinforcing sheets in loose-leaf binders have been longstanding, the prior art is devoid of any teaching of a method or apparatus for automatically and quickly applying reinforcing tabs to loose-leaf sheets without requiring the removal of the sheets from the loose-leaf binder. It is desirable to provide such a method and apparatus, and it is to this end that the present invention is directed.